what can stop fuel injector from working?

scan for codes and check fuel pressure first. 34 psi at idle w/vacuum 43 psi at idle w/o vacuum

engine want start how can i check fuel pressure at idle.

Try cranking engine to get fuel pressure. If you have pressure and injectors are not firing, it could be the cam sensor that is faulty. If you are able to get any trouble codes, that would most likely tell you what it is.

trouble codes or p1320, po325, po304

If 1995 2001 Maxima with 3.0L engine has MIL on & P1320 code (primary IGN signal) one or more ignition coils may have intermittent internal failure.
If also has single cylinder misfire code (P0301 P0306), replacing only coil on indicated cylinder should repair problem.
If only P1320 or P1320 & P0300, it may not be possible to determine which coil has failed. All coils may need to be replaced.
one of these is for cylinder 4 misfire, but it may be setting p0325 as well. also loosen then retighten ground by the injectors on the intake manifold. although you need to check to see if hte harness is broken and from reading the tips you have to use nissan coils only as the others won't stop the code. this one code p1320 is EXTEMELY hard to get rid of and you should really take this to a pro to straighten it out. this is only to save you money and frustrations this suggestion.

If engine had overheated previously, the knock sensor (P0325) is most probably bad. Check the wire socket for the knock to see if it is loose. The failure rate for this sensor is rather high.